title: Development of a sensitive and reliable high performance liquid chromatography method with fluorescence detection for high-throughput analysis of multi-class mycotoxins in Coix seed.
abstract: As an edible and medicinal plant, Coix seed is readily contaminated by more than one group of mycotoxins resulting in potential risk to human health. A reliable and sensitive method has been developed to determine seven mycotoxins (aflatoxins B1, B2, G1, G2, zearalenone, α-zearalenol, and β-zearalenol) simultaneously in 10 batches of Coix seed marketed in China. The method is based on a rapid ultrasound-assisted solid-liquid extraction (USLE) using methanol/water (80/20) followed by immunoaffinity column (IAC) clean-up, on-line photochemical derivatization (PCD), and high performance liquid chromatography coupled with fluorescence detection (HPLC-FLD). Careful optimization of extraction, clean-up, separation and detection conditions was accomplished to increase sample throughput and to attain rapid separation and sensitive detection. Method validation was performed by analyzing samples spiked at three different concentrations for the seven mycotoxins. Recoveries were from 73.5% to 107.3%, with relative standard deviations (RSDs) lower than 7.7%. The intra- and inter-day precisions, expressed as RSDs, were lower than 4% for all studied analytes. Limits of detection and quantification ranged from 0.01 to 50.2 μg kg(-1), and from 0.04 to 125.5 μg kg(-1), respectively, which were below the tolerance levels for mycotoxins set by the European Union. Samples that tested positive were further analyzed by HPLC tandem electrospray ionization mass spectrometry for confirmatory purposes. This is the first application of USLE-IAC-HPLC-PCD-FLD for detecting the occurrence of multi-class mycotoxins in Coix seed.
authors.affiliation: Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100193, China.
authors.forename: Wei-Jun
authors.initials: WJ
authors.lastname: Kong
authors.forename: Jun-Yuan
authors.initials: JY
authors.lastname: Li
authors.forename: Feng
authors.initials: F
authors.lastname: Qiu
authors.forename: Jian-He
authors.initials: JH
authors.lastname: Wei
authors.forename: Xiao-He
authors.initials: XH
authors.lastname: Xiao
authors.forename: Yuguo
authors.initials: Y
authors.lastname: Zheng
authors.forename: Mei-Hua
authors.initials: MH
authors.lastname: Yang
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000592:standards*; D031742:Coix / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D057166:High-Throughput Screening Assays / Q000379:methods*; D057230:Limit of Detection; D015394:Molecular Structure; D009183:Mycotoxins / Q000032:analysis*; D015203:Reproducibility of Results; D012639:Seeds / Q000737:chemistry*; D013997:Time Factors
chemical_list: D005456:Fluorescent Dyes; D009183:Mycotoxins
keywords: Coix seed; High performance liquid chromatography-fluorescence detection; High-throughput analysis; Method development; Multi-class mycotoxin